1
|
Zeleneva YV, Konkova EА. Soft wheat cultivars grown in the Saratov region and their resistance to Septoria blotch. Vavilovskii Zhurnal Genet Selektsii 2023; 27:582-590. [PMID: 38213467 PMCID: PMC10782035 DOI: 10.18699/vjgb-23-70] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/28/2023] [Accepted: 06/29/2023] [Indexed: 01/13/2024] Open
Abstract
Septoria is one of the harmful diseases of wheat cultivars cultivated in the Saratov region. This infectious disease of fungal etiology limits yield indicators and rapidly progresses in many regions of the Russian Federation. The aim of the research was to assess the resistance of winter and spring wheat cultivars that are referred to as promising and recommended for cultivation in the Low Volga region of the Russian Federation to pathogens of Septoria, to study the populations of Parastagonospora nodorum and P. pseudonodorum in the territory of the Saratov region in order to detect the presence of effector genes. Using molecular markers, we performed the identification of genes encoding NEs in 220 Parastagonospora spp. fungal isolates obtained from 7 cultivars of soft winter wheat, 6 taken from the winter triticale, 5 from soft spring wheat, 3 from durum spring wheat and 1 from spring oats. Among the P. nodorum isolates studied, there were both single genes Tox1, Tox3, and ToxA, and combinations of two genes in one genotype. The presence of the ToxA gene was not noted in the genotype of P. pseudonodorum isolates. During 2020-2022, a collection of winter and spring wheat cultivars was studied to detect resistance to Septoria blotch in field conditions (13 cultivars of winter wheat and 7 cultivars of spring wheat accordingly). The resistance of the cultivars was proven by laboratory evaluation. Three inoculums were used, including the isolates of Z. tritici, P. nodorum (ToxA, Tox1, Tox3), P. pseudonodorum (ToxA, Tox1, Tox3) mainly obtained from Saratov populations of 2022 (except for P. pseudonodorum with the ToxA gene). The tested cultivars were characterized using the Xfcp623 molecular marker, diagnostic for Tsn1/ tsn1 genes, which controls sensitivity to the fungal toxin of PtrToxA. Of greatest interest are 11 wheat genotypes that showed resistance to one, two and three species which served as causative agents of Septoria blotch (Zymoseptoria tritici, P. nodorum, P. pseudonodorum). These are the soft winter wheat cultivars Gostianum 237 (tsn1), Lutescens 230 (Tsn1), Guberniya (Tsn1), Podruga (Tsn1), Anastasia (Tsn1), Sosedka (Tsn1) and the soft spring wheat cultivars Favorit (tsn1), Prokhorovka (tsn1), Saratovskaya 70 (tsn1), Saratovskaya 73 (tsn1), Belyanka (tsn1). The results obtained are of interest as they might increase the efficiency of selection based on the elimination of genotypes with dominant Tsn1 alleles sensitive to PtrToxA. In addition to the economic value of the cultivars studied, it is recommended to use them in breeding for resistance to Septoria blotch.
Collapse
Affiliation(s)
- Yu V Zeleneva
- All-Russian Research Institute of Plant Protection, Pushkin, St. Petersburg, Russia
| | - E А Konkova
- Federal Center of Agriculture Research of the South-East Region, Saratov, Russia
| |
Collapse
|
2
|
Moolhuijzen PM, See PT, Shi G, Powell HR, Cockram J, Jørgensen LN, Benslimane H, Strelkov SE, Turner J, Liu Z, Moffat CS. A global pangenome for the wheat fungal pathogen Pyrenophora tritici-repentis and prediction of effector protein structural homology. Microb Genom 2022; 8:mgen000872. [PMID: 36214662 PMCID: PMC9676058 DOI: 10.1099/mgen.0.000872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The adaptive potential of plant fungal pathogens is largely governed by the gene content of a species, consisting of core and accessory genes across the pathogen isolate repertoire. To approximate the complete gene repertoire of a globally significant crop fungal pathogen, a pan genomic analysis was undertaken for Pyrenophora tritici-repentis (Ptr), the causal agent of tan (or yellow) spot disease in wheat. In this study, 15 new Ptr genomes were sequenced, assembled and annotated, including isolates from three races not previously sequenced. Together with 11 previously published Ptr genomes, a pangenome for 26 Ptr isolates from Australia, Europe, North Africa and America, representing nearly all known races, revealed a conserved core-gene content of 57 % and presents a new Ptr resource for searching natural homologues (orthologues not acquired by horizontal transfer from another species) using remote protein structural homology. Here, we identify for the first time a non-synonymous mutation in the Ptr necrotrophic effector gene ToxB, multiple copies of the inactive toxb within an isolate, a distant natural Pyrenophora homologue of a known Parastagonopora nodorum necrotrophic effector (SnTox3), and clear genomic break points for the ToxA effector horizontal transfer region. This comprehensive genomic analysis of Ptr races includes nine isolates sequenced via long read technologies. Accordingly, these resources provide a more complete representation of the species, and serve as a resource to monitor variations potentially involved in pathogenicity.
Collapse
Affiliation(s)
- Paula M. Moolhuijzen
- Centre for Crop Disease and Management, School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
- *Correspondence: Paula M. Moolhuijzen,
| | - Pao Theen See
- Centre for Crop Disease and Management, School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Gongjun Shi
- Department of Plant Pathology, North Dakota State University, Fargo, North Dakota, USA
| | - Harold R. Powell
- Department of Life Sciences, Centre for Integrative Systems Biology and Bioinformatics, Imperial College London, London, England, UK
| | - James Cockram
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
| | | | - Hamida Benslimane
- Département de Botanique, Ecole Nationale Supérieure Agronomique (ENSA), Hassan Badi, El-Harrach, Algiers, Algeria
| | - Stephen E. Strelkov
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | | | - Zhaohui Liu
- Department of Plant Pathology, North Dakota State University, Fargo, North Dakota, USA
- *Correspondence: Zhaohui Liu,
| | - Caroline S. Moffat
- Centre for Crop Disease and Management, School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
| |
Collapse
|
3
|
Hafez M, Despins T, Nakajima K, Aboukhaddour R. Identification of a Novel ToxA Haplotype of Pyrenophora tritici-repentis from Japan. PHYTOPATHOLOGY 2022; 112:1597-1602. [PMID: 35166575 DOI: 10.1094/phyto-01-22-0001-sc] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Pyrenophora tritici-repentis was described first as a pathogen of wheat (tan spot) in Japan in the 1920s, but, since then, no reports on P. tritici-repentis race structure or its effectors in Japan have been published. In this study, 10 single-spore isolates of P. tritici-repentis were collected from bread wheat in Japan. These isolates were evaluated for virulence on four differential wheat genotypes and tested for the presence/absence of the effector-encoding genes, ToxA and ToxB, in multiplex PCR assays. These isolates were identified as ToxA producers, of which eight were designated as race 2 (ToxA producers) and two were classified as race 1 (ToxA and ToxC producers) based on their virulence patterns. Sequence analysis of the ToxA amplicons from these 10 isolates indicated the presence of a novel ToxA haplotype (denoted PtrA2). A comparative sequence analysis and resequencing of ToxA from reference P. tritici-repentis isolates showed that all previously published ToxA haplotypes in P. tritici-repentis were identical, and are hence denoted PtrA1 in this study. A total of 163 PtrToxA sequences from global origins were already deposited in GenBank and were confirmed identical to PtrA1. Sequence variation in PtrA1 and PtrA2 open reading frames were found at three positions: one synonymous mutation at position 412 (C/G) and two nonsynonymous mutations at positions 342 and 362 that alter amino acid sequence. These mutations did not seem to affect the necrosis development on a ToxA-sensitive wheat genotype when rated for symptoms 5 to 7 days after inoculation. This is the first report correctly confirming the presence of an additional novel ToxA haplotype in P. tritici-repentis for which we have predicted its isoform and updated the ToxA haplotype evolutionary network.
Collapse
Affiliation(s)
- Mohamed Hafez
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Center, Lethbridge, Alberta, Canada
| | - Therese Despins
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Center, Lethbridge, Alberta, Canada
| | - Kaori Nakajima
- Mie Prefectural Agricultural Research Institute, Matsusaka, Japan
| | - Reem Aboukhaddour
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Center, Lethbridge, Alberta, Canada
| |
Collapse
|
4
|
Varietal Screening of Durum Wheat Varieties for Resistance to Pyrenophora tritici-repentis (Tan Spot) under Field Conditions. BIOMED RESEARCH INTERNATIONAL 2022; 2022:6433577. [PMID: 35669727 PMCID: PMC9167009 DOI: 10.1155/2022/6433577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 03/30/2022] [Accepted: 04/08/2022] [Indexed: 11/17/2022]
Abstract
Tan spot disease caused by Pyrenophora tritici-repentis was becoming more bred in Tunisia during the last decade. The search for resistant varieties against the increased virulence diversity of P. tritici-repentis is presently considered as a priority. Seven of the most commercialized durum wheat varieties in Tunisia (cvs. Maâli, Salim, Razzak, Monastir, Khiar, Inrat100, and Sculptur) were inoculated with five characterized fungal strains under field conditions, during two seasons. The variance analysis revealed that strains Ech8F6 and B4.8 used in inoculation are the most virulent ones. These strains hosting ToxB gene caused chlorosis symptom on the tested varieties. The other strains induced necrosis with yellow halo and host ToxA gene were less virulent. The area under disease progress curve values revealed that Maâli is the most vulnerable genotype compared to the new selected varieties Monastir and Inrat100. A variable tolerance rate of the varieties to tan spot disease was also highly visible on yield components. The losses were about 22.2% of the thousand kernel weight in Maâli variety, 35% of spikes/m2 in Inrat100 variety, 32.5% of kernel number/spike, and 25.2% of yield grain in Monastir variety. This effect evaluation of the strains harbouring ToxA and ToxB genes could be responsible for the identification of potentially susceptible genes Tsn1 and Tsc2 representing resistance sources for breeding programs.
Collapse
|
5
|
Characterization of Mediterranean Durum Wheat for Resistance to Pyrenophora tritici-repentis. Genes (Basel) 2022; 13:genes13020336. [PMID: 35205379 PMCID: PMC8872616 DOI: 10.3390/genes13020336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/03/2022] [Accepted: 02/04/2022] [Indexed: 02/04/2023] Open
Abstract
Tan spot (TS), caused by the fugus Pyrenophora tritici-repentis (Ptr), has gained significant importance in the last few years, thereby representing a threat to wheat production in all major wheat-growing regions, including Tunisia. In this context, we evaluated a Mediterranean collection of 549 durum wheat accessions under field conditions for resistance to Ptr over two cropping seasons in Jendouba (Tunisia), a hot spot for Ptr. The relative disease severities showed significant phenotypic variation from resistance to susceptibility. The correlation between disease scores over the two trials was significant, as 50% of the accessions maintained good levels of resistance (resistant–moderately resistant). Seedling and adult-stage reactions were significantly correlated. The ANOVA analysis revealed that the genotype term is highly significant at the adult stage, thus emphasizing the high genetic variability of the tested accessions. Reaction-type comparison among and between countries revealed a high diversity of TS resistance. Plant height (PH) was negatively correlated to disease scores, indicating that PH might either have a significant effect on TS severity or that it can be a potential disease escape trait. The evaluation of this collection allowed for the identification of potential diverse resistance sources to Ptr that can be incorporated in breeding programs.
Collapse
|
6
|
Laribi M, Akhavan A, Ben M'Barek S, Yahyaoui AH, Strelkov SE, Sassi K. Characterization of Pyrenophora tritici-repentis in Tunisia and Comparison with a Global Pathogen Population. PLANT DISEASE 2022; 106:464-474. [PMID: 34184550 DOI: 10.1094/pdis-04-21-0763-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Pyrenophora tritici-repentis causes tan spot, an important foliar disease of wheat. A collection of P. tritici-repentis isolates from Tunisia, located in one of the main secondary centers of diversification of durum wheat, was tested for phenotypic race classification based on virulence on a host differential set and for the presence of the necrotrophic effector (NE) genes ToxA, ToxB, and toxb by PCR analysis. While races 2, 4, 5, 6, 7, and 8 were identified according to their virulence phenotypes, PCR testing indicated the presence of "atypical" isolates that induced necrosis on the wheat differential 'Glenlea,' but lacked the expected ToxA gene, suggesting the involvement of other NEs in the P. tritici-repentis/wheat interaction. Genetic diversity and the P. tritici-repentis population structure were explored further by examining 59 Tunisian isolates and 35 isolates from Algeria, Azerbaijan, Canada, Iran, and Syria using 24 simple sequence repeat markers. Average genetic diversity, overall gene flow, and percentage polymorphic loci were estimated as 0.58, 2.09, and 87%, respectively. Analysis of molecular variance showed that 81% of the genetic variance occurred within populations and 19% occurred between populations. Cluster analysis by the unweighted pair group method indicated that ToxB- isolates grouped together and were distantly related to ToxB+ isolates. Based on Nei's analysis, the global collection clustered into two distinct groups according to their region of origin. The results suggest that geographic origin and the host specificity imposed by different NEs can lead to differentiation among P. tritici-repentis populations.
Collapse
Affiliation(s)
- Marwa Laribi
- University of Carthage, National Agronomic Institute of Tunisia, LR14AGR01 Laboratory of Genetic and Cereal Breeding, 1082 Tunis, Tunisia
- CRP Wheat Septoria Precision Phenotyping Platform, 1082 Tunis, Tunisia
| | - Alireza Akhavan
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada
| | - Sarrah Ben M'Barek
- CRP Wheat Septoria Precision Phenotyping Platform, 1082 Tunis, Tunisia
- Regional Field Crops Research Center of Beja BP 350, 9000 Béja, Tunisia
| | - Amor H Yahyaoui
- CRP Wheat Septoria Precision Phenotyping Platform, 1082 Tunis, Tunisia
- Centro Internacional de Mejoramiento de Maíz y Trigo, El Batán, CP 56237, México
| | - Stephen E Strelkov
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada
| | - Khaled Sassi
- University of Carthage, National Agronomic Institute of Tunisia, LR14AGR01 Laboratory of Genetic and Cereal Breeding, 1082 Tunis, Tunisia
| |
Collapse
|
7
|
Karunarathna A, Tibpromma S, Jayawardena RS, Nanayakkara C, Asad S, Xu J, Hyde KD, Karunarathna SC, Stephenson SL, Lumyong S, Kumla J. Fungal Pathogens in Grasslands. Front Cell Infect Microbiol 2021; 11:695087. [PMID: 34434901 PMCID: PMC8381356 DOI: 10.3389/fcimb.2021.695087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/21/2021] [Indexed: 01/02/2023] Open
Abstract
Grasslands are major primary producers and function as major components of important watersheds. Although a concise definition of grasslands cannot be given using a physiognomic or structural approach, grasslands can be described as vegetation communities experiencing periodical droughts and with canopies dominated by grasses and grass-like plants. Grasslands have a cosmopolitan distribution except for the Antarctic region. Fungal interactions with grasses can be pathogenic or symbiotic. Herbivorous mammals, insects, other grassland animals, and fungal pathogens are known to play important roles in maintaining the biomass and biodiversity of grasslands. Although most pathogenicity studies on the members of Poaceae have been focused on economically important crops, the plant-fungal pathogenic interactions involved can extend to the full range of ecological circumstances that exist in nature. Hence, it is important to delineate the fungal pathogen communities and their interactions in man-made monoculture systems and highly diverse natural ecosystems. A better understanding of the key fungal players can be achieved by combining modern techniques such as next-generation sequencing (NGS) together with studies involving classic phytopathology, taxonomy, and phylogeny. It is of utmost importance to develop experimental designs that account for the ecological complexity of the relationships between grasses and fungi, both above and below ground. In grasslands, loss in species diversity increases interactions such as herbivory, mutualism, predation or infectious disease transmission. Host species density and the presence of heterospecific host species, also affect the disease dynamics in grasslands. Many studies have shown that lower species diversity increases the severity as well as the transmission rate of fungal diseases. Moreover, communities that were once highly diverse but have experienced decreased species richness and dominancy have also shown higher pathogenicity load due to the relaxed competition, although this effect is lower in natural communities. This review addresses the taxonomy, phylogeny, and ecology of grassland fungal pathogens and their interactions in grassland ecosystems.
Collapse
Affiliation(s)
- Anuruddha Karunarathna
- Centre for Mountain Futures, Kunming Institute of Botany, Kunming, China.,Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, Chiang Mai, Thailand.,Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, Thailand
| | - Saowaluck Tibpromma
- Centre for Mountain Futures, Kunming Institute of Botany, Kunming, China.,CIFOR-ICRAF China Program, World Agroforestry (ICRAF), Kunming, China
| | - Ruvishika S Jayawardena
- Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, Thailand.,School of Science, Mae Fah Luang University, Chiang Rai, Thailand
| | | | - Suhail Asad
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, China
| | - Jianchu Xu
- Centre for Mountain Futures, Kunming Institute of Botany, Kunming, China.,CIFOR-ICRAF China Program, World Agroforestry (ICRAF), Kunming, China
| | - Kevin D Hyde
- Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, Thailand
| | - Samantha C Karunarathna
- Centre for Mountain Futures, Kunming Institute of Botany, Kunming, China.,CIFOR-ICRAF China Program, World Agroforestry (ICRAF), Kunming, China
| | - Steven L Stephenson
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, United States
| | - Saisamorn Lumyong
- Research Center of Microbial Diversity and Sustainable Utilization, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.,Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.,Academy of Science, The Royal Society of Thailand, Bangkok, Thailand
| | - Jaturong Kumla
- Research Center of Microbial Diversity and Sustainable Utilization, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.,Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
| |
Collapse
|
8
|
Kader KA, Hunger RM, Payton ME. Isolate Virulence and Cultivar Response in the Winter Wheat: Pyrenophora tritici-repentis (Tan Spot) Pathosystem in Oklahoma. THE PLANT PATHOLOGY JOURNAL 2021; 37:339-346. [PMID: 34365745 PMCID: PMC8357570 DOI: 10.5423/ppj.oa.01.2021.0012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/25/2021] [Accepted: 05/31/2021] [Indexed: 06/13/2023]
Abstract
Prevalence of tan spot of wheat caused by the fungus Pyrenophora tritici-repentis has become more prevalent in Oklahoma as no-till cultivation in wheat has increased. Hence, developing wheat varieties resistant to tan spot has been emphasized, and selecting pathogen isolates to screen for resistance to this disease is critical. Twelve isolates of P. tritici-repentis were used to inoculate 11 wheat cultivars in a greenhouse study in splitplot experiments. Virulence of isolates and cultivar resistance were measured in percent leaf area infection for all possible isolate x cultivar interactions. Isolates differed significantly (P < 0.01) in virulence on wheat cultivars, and cultivars differed significantly in disease reaction to isolates. Increased virulence of isolates detected increased variability in cultivar response (percent leaf area infection) (r = 0.56, P < 0.05) while increased susceptibility in cultivars detected increased variance in virulence of the isolates (r = 0.76, P < 0.01). A significant isolate × cultivar interaction indicated specificity between isolates and cultivars, however, cluster analysis indicated low to moderate physiological specialization. Similarity in wheat cultivars in response to pathogen isolates also was determined by cluster analysis. The use of diverse isolates of the fungus would facilitate evaluation of resistance in wheat cultivars to tan spot.
Collapse
Affiliation(s)
- Kazi A. Kader
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Robert M. Hunger
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Mark E. Payton
- Department of Statistics, Oklahoma State University, Stillwater, OK 74078, USA
| |
Collapse
|
9
|
Mironenko NV, Orina AS, Kovalenko NM. Nuclear Genetic Polymorphism in Pyrenophora tritici-repentis Strains for ToxA and ToxB Effector Genes. RUSS J GENET+ 2021. [DOI: 10.1134/s1022795421040098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
10
|
Kariyawasam GK, Wyatt N, Shi G, Liu S, Yan C, Ma Y, Zhong S, Rasmussen JB, Moolhuijzen P, Moffat CS, Friesen TL, Liu Z. A genome-wide genetic linkage map and reference quality genome sequence for a new race in the wheat pathogen Pyrenophora tritici-repentis. Fungal Genet Biol 2021; 152:103571. [PMID: 34015431 DOI: 10.1016/j.fgb.2021.103571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 02/23/2021] [Accepted: 03/01/2021] [Indexed: 10/21/2022]
Abstract
Pyrenophora tritici-repentis is an ascomycete fungus that causes tan spot of wheat. The disease has a worldwide distribution and can cause significant yield and quality losses in wheat production. The fungal pathogen is homothallic in nature, which means it can undergo sexual reproduction by selfing to produce pseudothecia on wheat stubble for seasonal survival. Since homothallism precludes the development of bi-parental fungal populations, no genetic linkage map has been developed for P. tritici-repentis for mapping and map-based cloning of fungal virulence genes. In this work, we created two heterothallic strains by deleting one of the mating type genes in each of two parental isolates 86-124 (race 2) and AR CrossB10 (a new race) and developed a bi-parental fungal population between them. The draft genome sequences of the two parental isolates were aligned to the Pt-1C-BFP reference sequence to mine single nucleotide polymorphisms (SNPs). A total of 225 SNP markers were developed for genotyping the entire population. Additionally, 75 simple sequence repeat, and two gene markers were also developed and used in the genotyping. The resulting linkage map consisted of 13 linkage groups spanning 5,075.83 cM in genetic distance. Because the parental isolate AR CrossB10 is a new race and produces Ptr ToxC, it was sequenced using long-read sequencing platforms and de novo assembled into contigs. The majority of the contigs were further anchored into chromosomes with the aid of the linkage maps. The whole genome comparison of AR CrossB10 to the reference genome of M4 revealed a few chromosomal rearrangements. The genetic linkage map and the new AR CrossB10 genome sequence are valuable tools for gene cloning in P. tritici-repentis.
Collapse
Affiliation(s)
- Gayan K Kariyawasam
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA
| | - Nathan Wyatt
- USDA-ARS Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Fargo, ND 58102, USA
| | - Gongjun Shi
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA
| | - Sanzhen Liu
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA
| | - Changhui Yan
- Department of Computer Science, North Dakota State University, Fargo, ND 58108, USA
| | - Yongchao Ma
- Department of Computer Science, North Dakota State University, Fargo, ND 58108, USA
| | - Shaobin Zhong
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA
| | - Jack B Rasmussen
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA
| | - Paula Moolhuijzen
- Center for Crop Disease and Management, Department of Environment and Agriculture, Curtin University, Bentley, Western Australia, Australia
| | - Caroline S Moffat
- Center for Crop Disease and Management, Department of Environment and Agriculture, Curtin University, Bentley, Western Australia, Australia
| | - Timothy L Friesen
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA; USDA-ARS Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Fargo, ND 58102, USA
| | - Zhaohui Liu
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA.
| |
Collapse
|
11
|
Hafez M, Gourlie R, Despins T, Turkington TK, Friesen TL, Aboukhaddour R. Parastagonospora nodorum and Related Species in Western Canada: Genetic Variability and Effector Genes. PHYTOPATHOLOGY 2020; 110:1946-1958. [PMID: 32689900 DOI: 10.1094/phyto-05-20-0207-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Parastagonospora nodorum is an important fungal pathogen that causes Septoria nodorum blotch (SNB) in wheat. This pathogen produces several necrotrophic effectors that act as virulence factors; three have been cloned, SnToxA, SnTox1, and SnTox3. In this study, P. nodorum and its sister species P. avenaria f. tritici (Pat1) were isolated from wheat node and grain samples collected from distanced sites in western Canada during 2018. The presence of effector genes and associated haplotypes were determined by PCR and sequence analysis. An internal transcribed spacer-restriction fragment length polymorphism test was developed to distinguish between leaf spotting pathogens (P. nodorum, Pat1, Pyrenophora tritici-repentis, and Bipolaris sorokiniana). P. nodorum was mainly recovered from wheat nodes and to a lesser extent from the grains, while Pat1 was exclusively isolated from grain samples. The effector genes were present in almost all P. nodorum isolates, with the ToxA haplotype 5 (H5) being most prevalent, while a novel ToxA haplotype (denoted here H21) is reported for the first time. In Pat1, only combinations of SnTox1 and SnTox3 genes were present. A ToxA haplotype network was also constructed to assess the evolutionary relationship among globally found haplotypes to date. Finally, cultivars representing wheat development in Canada for the last century were tested for sensitivity to Sn-effectors and to the presence of Tsn1, the ToxA sensitivity gene. Of tested cultivars, 32.9 and 56.9% were sensitive to SnTox1 and SnTox3, respectively, and Tsn1 was present in 59% of the cultivars. In conclusion, P. nodorum and Pat1 were prevalent wheat pathogens in Canada with a potential tissue-specific colonization capacity, while producing necrotrophic effectors to which wheat is sensitive.
Collapse
Affiliation(s)
- Mohamed Hafez
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Center, Lethbridge, Alberta, Canada (working address)
- Department of Botany and Microbiology, Faculty of Science, Suez University, Suez, Egypt (permanent address)
| | - Ryan Gourlie
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Center, Lethbridge, Alberta, Canada (working address)
| | - Therese Despins
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Center, Lethbridge, Alberta, Canada (working address)
| | - Thomas K Turkington
- Agriculture and Agri-Food Canada, Lacombe Research and Development Center, Lacombe, Alberta, Canada
| | - Timothy L Friesen
- U.S. Department of Agriculture, Agricultural Research Service, Edward T. Schafer Agricultural Research Center, Fargo, ND, U.S.A
| | - Reem Aboukhaddour
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Center, Lethbridge, Alberta, Canada (working address)
| |
Collapse
|
12
|
Wei B, Moscou MJ, Sato K, Gourlie R, Strelkov S, Aboukhaddour R. Identification of a Locus Conferring Dominant Susceptibility to Pyrenophora tritici-repentis in Barley. FRONTIERS IN PLANT SCIENCE 2020; 11:158. [PMID: 32180780 PMCID: PMC7059616 DOI: 10.3389/fpls.2020.00158] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 01/31/2020] [Indexed: 05/17/2023]
Abstract
The fungus Pyrenophora tritici-repentis (Ptr) causes tan spot, a destructive foliar disease of wheat worldwide. The pathogen produces several necrotrophic effectors, which induce necrosis or chlorosis on susceptible wheat lines. Multiple races of Ptr have been identified, based on their ability to produce one or more of these effectors. Ptr has a wide host range of cereal and non-cereal grasses, but is known to cause damage only on wheat. Previously, we showed that Ptr can interact specifically with cultivated barley (Hordeum vulgare ssp. vulgare), and that the necrotrophic effector Ptr ToxB induces mild chlorosis in a highly selective manner when infiltrated into certain barley genotypes. In the present study, a barley doubled-haploid (DH) population was evaluated for reaction to Ptr race 5, a Ptr ToxB-producer. Then a comprehensive genetic map composed of 381 single nucleotide polymorphism (SNP) markers was used to map the locus conditioning this chlorosis. The F1 seedlings, and 92 DH lines derived from a cross between the resistant Japanese malting barley cultivar Haruna Nijo and the susceptible wild barley (H. vulgare ssp. spontaneum) OUH602 were inoculated with a conidial suspension of Ptr race 5 isolate at the two-leaf stage. The seedlings were monitored daily for symptoms and assessed for chlorosis development on the second leaf, 6 days after inoculation. All tested F1 seedlings exhibited chlorosis symptoms similar to the susceptible parent, and the DH lines segregated 1:1 for susceptible:resistant phenotypes, indicating the involvement of a single locus. Marker-trait linkage analysis based on interval mapping identified a single locus on the distal region of the short arm of chromosome 2H. We designate this locus Susceptibility to P. tritici-repentis1 (Spr1). The region encompassing this locus has 99 high confidence gene models, including membrane receptor-like kinases (RLKs), intracellular nucleotide-binding, leucine-rich repeat receptors (NLRs), and ankyrin-repeat proteins (ANKs). This shows the involvement of a dominant locus conferring susceptibility to Ptr in barley. Further work using high-resolution mapping and transgenic complementation will be required to identify the underlying gene.
Collapse
Affiliation(s)
- Bohan Wei
- Cereal Pathology Lab, Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, Canada
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Matthew J. Moscou
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Kazuhiro Sato
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Ryan Gourlie
- Cereal Pathology Lab, Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, Canada
| | - Stephen Strelkov
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Reem Aboukhaddour
- Cereal Pathology Lab, Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, Canada
- *Correspondence: Reem Aboukhaddour,
| |
Collapse
|
13
|
Kamel S, Cherif M, Hafez M, Despins T, Aboukhaddour R. Pyrenophora tritici-repentis in Tunisia: Race Structure and Effector Genes. FRONTIERS IN PLANT SCIENCE 2019; 10:1562. [PMID: 31921233 PMCID: PMC6930679 DOI: 10.3389/fpls.2019.01562] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 11/07/2019] [Indexed: 06/10/2023]
Abstract
Tan spot is a destructive foliar wheat disease worldwide and caused by the ascomycete fungus Pyrenophora tritici-repentis (Ptr); it has become more frequent in Tunisia over the last decade. In this study, the virulence of 73 single-spore isolates, collected from durum and bread wheat fields during 2017-2018 growing season, was evaluated on four differential wheat genotypes. This was followed by polymerase chain reaction tests with specific primers for the effector genes ToxA, ToxB, and toxb (ToxB-homolog). Sequence analysis to validate the identity of the amplified genes was followed, and ToxA amplicons from a subset of 22 isolates were analyzed to determine its haplotype identity. Ptr isolates from Tunisia were grouped in races 2, 4, 5, and 7, and 44% of the tested isolates did not fit under any known race, and were denoted here as atypical. These atypical isolates induced the same symptoms as race 7 isolates, extensive necrosis, and chlorosis on susceptible genotypes, but lacked the ToxA gene. ToxA is the only identified necrosis-inducing effector in Ptr, and was amplified in 51% of tested isolates, and shared identical sequence to previously identified haplotype (H15). ToxB and its homolog toxb were present in 97% and 93% of tested isolates, respectively. Ptr in Tunisia lacked Ptr ToxC activity, and none of the tested isolates induced the specific symptoms of that effector. Race 7 and the atypical isolates dominated the Tunisian Ptr population, while races 2, 4, and 5 were found at low percentages. In conclusion, ToxB and its homolog were the most dominant genes in Ptr from Tunisia, and the majority of the isolates induced necrosis and chlorosis on Ptr ToxA and Ptr ToxB susceptible wheat genotypes. However, only about half of that necrosis can be attributed to ToxA presence, this result necessitates further research to investigate the prevalence of additional necrotic effector(s). Terminology: in this paper, Pyrenophora tritici-repentis abbreviated as Ptr, the effectors are referred to by Ptr ToxA, Ptr ToxB and Ptr ToxC, and the genes coding for them are written in italic as ToxA, ToxB, and ToxC, respectively.
Collapse
Affiliation(s)
- Sana Kamel
- Laboratory of Genetics and Cereal Breeding, Department of Agronomy and Plant Biotechnology, National Agronomic Institute of Tunisia, University of Carthage, Tunis, Tunisia
| | - Mejda Cherif
- Laboratory of Genetics and Cereal Breeding, Department of Agronomy and Plant Biotechnology, National Agronomic Institute of Tunisia, University of Carthage, Tunis, Tunisia
| | - Mohamed Hafez
- Cereal Pathology Lab, Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, Canada
| | - Therese Despins
- Cereal Pathology Lab, Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, Canada
| | - Reem Aboukhaddour
- Cereal Pathology Lab, Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, Canada
| |
Collapse
|
14
|
Singh PK, Singh S, Deng Z, He X, Kehel Z, Singh RP. Characterization of QTLs for Seedling Resistance to Tan Spot and Septoria Nodorum Blotch in the PBW343/Kenya Nyangumi Wheat Recombinant Inbred Lines Population. Int J Mol Sci 2019; 20:E5432. [PMID: 31683619 PMCID: PMC6862150 DOI: 10.3390/ijms20215432] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 10/25/2019] [Accepted: 10/28/2019] [Indexed: 11/25/2022] Open
Abstract
Tan spot (TS) and Septoria nodorum blotch (SNB) induced by Pyrenophora tritici-repentis and Parastagonospora nodorum, respectively, cause significant yield losses and adversely affect grain quality. The objectives of this study were to decipher the genetics and map the resistance to TS and SNB in the PBW343/Kenya Nyangumi (KN) population comprising 204 F6 recombinant inbred lines (RILs). Disease screening was performed at the seedling stage under greenhouse conditions. TS was induced by P. tritici-repentis isolate MexPtr1 while SNB by P. nodorum isolate MexSN1. Segregation pattern of the RILs indicated that resistance to TS and SNB in this population was quantitative. Diversity Array Technology (DArTs) and simple sequence repeats (SSRs) markers were used to identify the quantitative trait loci (QTL) for the diseases using inclusive composite interval mapping (ICIM). Seven significant additive QTLs for TS resistance explaining 2.98 to 23.32% of the phenotypic variation were identified on chromosomes 1A, 1B, 5B, 7B and 7D. For SNB, five QTLs were found on chromosomes 1A, 5A, and 5B, explaining 5.24 to 20.87% of the phenotypic variation. The TS QTL on 1B chromosome coincided with the pleiotropic adult plant resistance (APR) gene Lr46/Yr29/Pm39. This is the first report of the APR gene Lr46/Yr29/Pm39 contributing to TS resistance.
Collapse
Affiliation(s)
- Pawan Kumar Singh
- International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6-641, México 06600, D.F., Mexico.
| | - Sukhwinder Singh
- International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6-641, México 06600, D.F., Mexico.
| | - Zhiying Deng
- International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6-641, México 06600, D.F., Mexico.
- State Key Laboratory of Crop Biology, Cooperation Innovation Center of Efficient Production with High Annual Yield of Wheat and Corn, Shandong Agricultural University, Taian 271018, China.
| | - Xinyao He
- International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6-641, México 06600, D.F., Mexico.
| | - Zakaria Kehel
- International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6-641, México 06600, D.F., Mexico.
| | - Ravi Prakash Singh
- International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6-641, México 06600, D.F., Mexico.
| |
Collapse
|
15
|
Kokhmetova AМ, Ali S, Sapakhova Z, Atishova MN. Identifcation of genotypescarriers of resistance to tan spot Ptr ToxA and Ptr ToxB of Pyrenophora tritici-repentis in common wheat collection. Vavilovskii Zhurnal Genet Selektsii 2019. [DOI: 10.18699/vj18.440] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Pyrenophora tritici-repentis(Ptr) is the causative agent of tan spot, one of the yield limiting diseases of wheat, rapidly increasing in wheat growing countries including Kazakhstan. The aim of this study was the identifcation of wheat genotypes with resistance to Ptr race 1 and race 5 and their hostselective effectors (toxins) Ptr ToxA and Ptr ToxB. A common wheat collection of 41 accessions (38 experimental and 3 controls) was characterized using the molecular markersXfcp623andXBE444541, diagnostic for theTsn1andTsc2genes conferring sensitivity to fungal toxins. The coincidence of the markerXBE444541with resistance to race 5 was 92.11 %, and with Ptr ToxB, 97.37 %. Genotyping results using the markerXfcp623confrmed the expected response to Ptr ToxA; the presence/absence of the markerXfcp623completely (100 %) coincided with sensitivity/resistance to race 1 and Ptr ToxA. This demonstrates the reliability of the diagnostic markerXfcp623for identifying wheat genotypes with resistance to the fungus and insensitivity to Ptr ToxA. The study of the reaction of wheat germplasm to the fungal inoculation and toxin infltration showed that out of 38 genotypes analyzed 30 (78 %) exhibited resistance to both race 1 and race 5, and insensitivity to toxins Ptr ToxA and ToxB. Of most signifcant interest are eight wheat genotypes that showed resistance/insensitivity both to the two races and two toxins. The results of phenotyping were reconfrmed by the molecular markers used in this study. Sensitivity to Ptr ToxB is not always correlated with susceptibility to race 5 and is dependent on the host’s genetic background of the wheat genotype, i. e. on a specifc wheat genotype. The results of the study are of interest for increasing the efciency of breeding based on the elimination of the genotypes with the dominant allelesTsn1andTsc2sensitive to the toxins Ptr ToxA and ToxB. The genotypes identifed will be used in wheat breeding for resistance to tan spot.
Collapse
Affiliation(s)
| | - Sh. Ali
- South Dakota State University
| | | | | |
Collapse
|
16
|
Guo J, Shi G, Liu Z. Characterizing Virulence of the Pyrenophora tritici-repentis Isolates Lacking Both ToxA and ToxB Genes. Pathogens 2018; 7:E74. [PMID: 30213041 PMCID: PMC6161158 DOI: 10.3390/pathogens7030074] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/05/2018] [Accepted: 09/10/2018] [Indexed: 11/30/2022] Open
Abstract
The fungus Pyrenophora tritici-repentis (Ptr) causes tan spot of wheat crops, which is an important disease worldwide. Based on the production of the three known necrotrophic effectors (NEs), the fungal isolates are classified into eight races with race 4 producing no known NEs. From a laboratory cross between 86⁻124 (race 2 carrying the ToxA gene for the production of Ptr ToxA) and DW5 (race 5 carrying the ToxB gene for the production of Ptr ToxB), we have obtained some Ptr isolates lacking both the ToxA and ToxB genes, which, by definition, should be classified as race 4. In this work, we characterized virulence of two of these isolates called B16 and B17 by inoculating them onto various common wheat (Triticum aestivum L.) and durum (T. turgidum L.) genotypes. It was found that the two isolates still caused disease on some genotypes of both common and durum wheat. Disease evaluations were also conducted in recombinant inbred line populations derived from two hard red winter wheat cultivars: Harry and Wesley. QTL mapping in this population revealed that three genomic regions were significantly associated with disease, which are different from the three known NE sensitivity loci. This result further indicates the existence of other NE-host sensitivity gene interactions in the wheat tan spot disease system.
Collapse
Affiliation(s)
- Jingwei Guo
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA.
| | - Gongjun Shi
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA.
| | - Zhaohui Liu
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA.
| |
Collapse
|
17
|
Benslimane H. Virulence Phenotyping and Molecular Characterization of a New Virulence Type of Pyrenophora tritici-repentis the Causal Agent of Tan Spot. THE PLANT PATHOLOGY JOURNAL 2018; 34:139-142. [PMID: 29628820 PMCID: PMC5880358 DOI: 10.5423/ppj.nt.07.2017.0150] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 10/28/2017] [Accepted: 12/11/2017] [Indexed: 05/21/2023]
Abstract
Pyrenophoratritici-repentis is the causal agent of tan spot. According to their ability to produce necrosis and/or chlorosis on a set of four differential bread wheats, the isolates of this fungus are currently grouped into eight races. When durum wheat genotypes were added to the differential set, a new virulence type was identified in Algeria. The isolates showing this virulence pattern are unable to attack bread wheat while they cause necrosis in durum genotypes. In this work, characterization of those isolates was based on pathological and molecular aspects. This included inoculation of bread and durum wheat, and virulence gene analysis using PCR and sequencing. The results showed that all isolates caused a resistance on all bread wheats of the differential set, while they produced necrosis in durum. ToxA and ToxB genes were amplified in all isolates, whereas toxb was absent. Sequence analysis for both genes showed no differences with those found in the two functional genes. The presence of two genes, ToxA and ToxB, despite the absence of symptoms usually caused by their products, suggests the existence of a new homologous for these two genes yet unknown. The presence of ToxA in the isolate unable to produce necrosis in Glenlea is reported for the first time.
Collapse
Affiliation(s)
- Hamida Benslimane
- Corresponding author. Phone) +213(0)-554-583-229, FAX) +213(0)-2382-8503/04, E-mail)
| |
Collapse
|
18
|
Comparative Methods for Molecular Determination of Host-Specificity Factors in Plant-Pathogenic Fungi. Int J Mol Sci 2018; 19:ijms19030863. [PMID: 29543717 PMCID: PMC5877724 DOI: 10.3390/ijms19030863] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 03/12/2018] [Accepted: 03/14/2018] [Indexed: 12/11/2022] Open
Abstract
Many plant-pathogenic fungi are highly host-specific. In most cases, host-specific interactions evolved at the time of speciation of the respective host plants. However, host jumps have occurred quite frequently, and still today the greatest threat for the emergence of new fungal diseases is the acquisition of infection capability of a new host by an existing plant pathogen. Understanding the mechanisms underlying host-switching events requires knowledge of the factors determining host-specificity. In this review, we highlight molecular methods that use a comparative approach for the identification of host-specificity factors. These cover a wide range of experimental set-ups, such as characterization of the pathosystem, genotyping of host-specific strains, comparative genomics, transcriptomics and proteomics, as well as gene prediction and functional gene validation. The methods are described and evaluated in view of their success in the identification of host-specificity factors and the understanding of their functional mechanisms. In addition, potential methods for the future identification of host-specificity factors are discussed.
Collapse
|
19
|
Ameen G, Kariyawasam G, Shi G, Friesen TL, Faris JD, Ali S, Rasmussen JB, Liu Z. Molecular manipulation of the mating-type system and development of a new approach for characterizing pathogen virulence in Pyrenophora tritici-repentis. Fungal Genet Biol 2017; 109:16-25. [DOI: 10.1016/j.fgb.2017.10.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 10/12/2017] [Accepted: 10/14/2017] [Indexed: 02/03/2023]
|
20
|
Abdullah S, Sehgal SK, Glover KD, Ali S. Reaction of Global Collection of Rye ( Secale cereale L.) to Tan Spot and Pyrenophora tritici-repentis Races in South Dakota. THE PLANT PATHOLOGY JOURNAL 2017; 33:229-237. [PMID: 28592942 PMCID: PMC5461042 DOI: 10.5423/ppj.oa.12.2016.0265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 03/14/2017] [Accepted: 03/14/2017] [Indexed: 06/07/2023]
Abstract
Rye (Secale cereale L.) serves as an alternative host of Pyrenophora tritici-repentis (PTR) the cause of tan spot on wheat. Rye is cultivated as a forage or cover crop and overlaps with a significant portion of wheat acreage in the U.S. northern Great Plains; however, it is not known whether the rye crop influences the evolution of PTR races. We evaluated a global collection of 211 rye accessions against tan spot and assessed the diversity in PTR population on rye in South Dakota. All the rye genotypes were inoculated with PTR races 1 and 5, and infiltrated with Ptr ToxA and Ptr ToxB, at seedling stage. We observed 21% of the genotypes exhibited susceptibility to race 1, whereas, 39% were susceptible to race 5. All 211 accessions were insensitive to both the Ptr toxins. It indicates that though rye exhibits diversity in reaction to tan spot, it lacks Ptr ToxA and ToxB sensitivity genes. This suggests that unknown toxins or other factors can lead to PTR establishment in rye. We characterized the race structure of 103 PTR isolates recovered from rye in South Dakota. Only 22% of the isolates amplified Ptr ToxA gene and were identified as race 1 based on their phenotypic reaction on the differential set. The remaining 80 isolates were noted to be race 4. Our results show that races 1 and 4 are prevalent on rye in South Dakota with a higher frequency of race 4, suggesting a minimal role of rye in the disease epidemiology.
Collapse
Affiliation(s)
- Sidrat Abdullah
- Department of Agronomy, Horticulture, and Plant Science, South Dakota State University, Brookings, SD 57007,
USA
| | - Sunish K. Sehgal
- Department of Agronomy, Horticulture, and Plant Science, South Dakota State University, Brookings, SD 57007,
USA
| | - Karl D. Glover
- Department of Agronomy, Horticulture, and Plant Science, South Dakota State University, Brookings, SD 57007,
USA
| | - Shaukat Ali
- Department of Agronomy, Horticulture, and Plant Science, South Dakota State University, Brookings, SD 57007,
USA
| |
Collapse
|
21
|
Abdullah S, Sehgal SK, Ali S, Liatukas Z, Ittu M, Kaur N. Characterization of Pyrenophora tritici-repentis (Tan Spot of Wheat) Races in Baltic States and Romania. THE PLANT PATHOLOGY JOURNAL 2017; 33:133-139. [PMID: 28381960 PMCID: PMC5378434 DOI: 10.5423/ppj.oa.10.2016.0214] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 11/10/2016] [Accepted: 12/11/2016] [Indexed: 05/07/2023]
Abstract
Tan spot, caused by the fungus Pyrenophora triticirepentis, is economically important foliar disease in Latvia, Lithuania, and Romania; however, race structure from Baltic States and Romania is not known. In this study, we performed genotypic and phenotypic race characterization of a large collection of P. triticirepentis isolates from these countries to determine race structure and utilize this information for better disease management and breeding wheat for tan spot resistance. We characterized 231 single spore isolates from Latvia (n = 15), Lithuania (n = 107), and Romania (n = 109) for Ptr ToxA and Ptr ToxB genes using two genes specific primers. A subset (139) of 231 isolates were further characterized for their race structure by inoculating them individually on tan spot wheat differentials set. Majority (83%) of the 231 isolates amplified Ptr ToxA gene suggesting prevalence of race 1 and 2. Further, phenotypic characterization of 139 isolates also showed wide prevalence of races 1 (68%), 2 (8%), 3 (11%), and 4 (5%) were also identified from Baltic States as well as Romania. Eighteen of the isolates (13%) did not seem to be of any of the eight known races as they lacked Ptr ToxA gene but they behaved like either race 1 or race 2, suggesting possibility of novel toxins in these isolates as their virulence tools.
Collapse
Affiliation(s)
- Sidrat Abdullah
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD 57006,
USA
| | - Sunish Kumar Sehgal
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD 57006,
USA
| | - Shaukat Ali
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD 57006,
USA
| | - Zilvinas Liatukas
- Institute of Agriculture, Lithuanian Research Center for Agriculture and Forestry, Kėdainiai 58344,
Lithuania
| | - Mariana Ittu
- National Agricultural Research and Development Institute Fundulea, Fundulea 915200,
Romania
| | - Navjot Kaur
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD 57006,
USA
| |
Collapse
|
22
|
Abdullah S, Sehgal SK, Jin Y, Turnipseed B, Ali S. Insights into Tan Spot and Stem Rust Resistance and Susceptibility by Studying the Pre-Green Revolution Global Collection of Wheat. THE PLANT PATHOLOGY JOURNAL 2017; 33:125-132. [PMID: 28381959 PMCID: PMC5378433 DOI: 10.5423/ppj.oa.07.2016.0157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/02/2016] [Accepted: 11/06/2016] [Indexed: 05/12/2023]
Abstract
Tan spot (TS), caused by the fungus Pyrenophora tritici-repentis (Died) Drechs, is an important foliar disease of wheat and has become a threat to world wheat production since the 1970s. In this study a globally diverse pre-1940s collection of 247 wheat genotypes was evaluated against Ptr ToxA, P. tritici-repentis race 1, and stem rust to determine if; (i) acquisition of Ptr ToxA by the P. tritici-repentis from Stagonospora nodorum led to increased pathogen virulence or (ii) incorporation of TS susceptibility during development stem rust resistant cultivars led to an increase in TS epidemics globally. Most genotypes were susceptible to stem rust; however, a range of reactions to TS and Ptr ToxA were observed. Four combinations of disease-toxin reactions were observed among the genotypes; TS susceptible-Ptr ToxA sensitive, TS susceptible-Ptr ToxA insensitive, TS resistant-Ptr ToxA insensitive, and TS resistant-Ptr ToxA toxin sensitive. A weak correlation (r = 0.14 for bread wheat and -0.082 for durum) was observed between stem rust susceptibility and TS resistance. Even though there were no reported epidemics in the pre-1940s, TS sensitive genotypes were widely grown in that period, suggesting that Ptr ToxA may not be an important factor responsible for enhanced prevalence of TS.
Collapse
Affiliation(s)
- Sidrat Abdullah
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD 57007,
USA
| | - Sunish Kumar Sehgal
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD 57007,
USA
| | - Yue Jin
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Cereal Disease Laboratory, University of Minnesota, St. Paul, MN 55108,
USA
| | - Brent Turnipseed
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD 57007,
USA
| | - Shaukat Ali
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD 57007,
USA
| |
Collapse
|
23
|
See PT, Moffat CS, Morina J, Oliver RP. Evaluation of a Multilocus Indel DNA Region for the Detection of the Wheat Tan Spot Pathogen Pyrenophora tritici-repentis. PLANT DISEASE 2016; 100:2215-2225. [PMID: 30682909 DOI: 10.1094/pdis-03-16-0262-re] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Tan spot or yellow (leaf) spot disease of wheat (Triticum spp.) is caused by Pyrenophora tritici-repentis, a necrotrophic fungal pathogen that is widespread throughout the main wheat-growing regions in the world. This disease is currently the single most economically important crop disease in Australia. In this study, a real-time quantitative polymerase chain reaction (qPCR) assay was developed as a diagnostic tool to detect the pathogen on wheat foliar tissue. A multicopy locus (PtrMulti) present in the P. tritici-repentis genome was assessed for its suitability as a qPCR probe. The primer pair PtrMulti_F/R that targets the region was evaluated with respect to species specificity and sensitivity. A PtrMulti SYBR qPCR assay was developed and proved to be suitable for the identification and relative quantification of P. tritici-repentis with a detection limit of DNA levels at <0.1 pg. Variation of the PtrMulti copy number between the geographical representatives of P. tritici-repentis strains examined was minimal, with the range of 63 to 85 copies per genome. For naturally infected wheat field samples, the incidence of P. tritici-repentis DNA on leaves quantified by qPCR varied up to 1,000-fold difference in the concentration, with a higher incidence of DNA occurring on the lower canopy for most of the growth stages examined. At the early growth stages, qPCR assay was able to detect P. tritici-repentis DNA on the younger leaves in the absence of visible tan spot lesions. These results demonstrate the potential of PtrMulti probe to be used for early detection and rapid screening of tan spot disease on wheat plants.
Collapse
Affiliation(s)
- Pao Theen See
- Centre for Crop and Disease Management, Department of Environment and Agriculture, School of Science, Curtin University, Bentley, WA 6102, Australia
| | - Caroline S Moffat
- Centre for Crop and Disease Management, Department of Environment and Agriculture, School of Science, Curtin University, Bentley, WA 6102, Australia
| | - Joseph Morina
- Centre for Crop and Disease Management, Department of Environment and Agriculture, School of Science, Curtin University, Bentley, WA 6102, Australia
| | - Richard P Oliver
- Centre for Crop and Disease Management, Department of Environment and Agriculture, School of Science, Curtin University, Bentley, WA 6102, Australia
| |
Collapse
|
24
|
Manning VA, Ciuffetti LM. Necrotrophic effector epistasis in the Pyrenophora tritici-repentis-wheat interaction. PLoS One 2015; 10:e0123548. [PMID: 25845019 PMCID: PMC4386829 DOI: 10.1371/journal.pone.0123548] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 03/05/2015] [Indexed: 11/25/2022] Open
Abstract
Pyrenophora tritici-repentis, the causal agent of tan spot disease of wheat, mediates disease by the production of host-selective toxins (HST). The known toxins are recognized in an 'inverse' gene-for-gene manner, where each is perceived by the product of a unique locus in the host and recognition leads to disease susceptibility. Given the importance of HSTs in disease development, we would predict that the loss of any of these major pathogenicity factors would result in reduced virulence and disease development. However, after either deletion of the gene encoding the HST ToxA or, reciprocally, heterologous expression of ToxA in a race that does not normally produce the toxin followed by inoculation of ToxA-sensitive and insensitive wheat cultivars, we demonstrate that ToxA symptom development can be epistatic to other HST-induced symptoms. ToxA epistasis on certain ToxA-sensitive wheat cultivars leads to genotype-specific increases in total leaf area affected by disease. These data indicate a complex interplay between host responses to HSTs in some genotypes and underscore the challenge of identifying additional HSTs whose activity may be masked by other toxins. Also, through mycelial staining, we acquire preliminary evidence that ToxA may provide additional benefits to fungal growth in planta in the absence of its cognate recognition partner in the host.
Collapse
Affiliation(s)
- Viola A. Manning
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Lynda M. Ciuffetti
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
- Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
| |
Collapse
|
25
|
Déon M, Fumanal B, Gimenez S, Bieysse D, Oliveira RR, Shuib SS, Breton F, Elumalai S, Vida JB, Seguin M, Leroy T, Roeckel-Drevet P, Pujade-Renaud V. Diversity of the cassiicolin gene in Corynespora cassiicola and relation with the pathogenicity in Hevea brasiliensis. Fungal Biol 2014; 118:32-47. [DOI: 10.1016/j.funbio.2013.10.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 10/16/2013] [Accepted: 10/29/2013] [Indexed: 10/26/2022]
|
26
|
Dalman K, Himmelstrand K, Olson Å, Lind M, Brandström-Durling M, Stenlid J. A genome-wide association study identifies genomic regions for virulence in the non-model organism Heterobasidion annosum s.s. PLoS One 2013; 8:e53525. [PMID: 23341945 PMCID: PMC3547014 DOI: 10.1371/journal.pone.0053525] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 12/03/2012] [Indexed: 12/02/2022] Open
Abstract
The dense single nucleotide polymorphisms (SNP) panels needed for genome wide association (GWA) studies have hitherto been expensive to establish and use on non-model organisms. To overcome this, we used a next generation sequencing approach to both establish SNPs and to determine genotypes. We conducted a GWA study on a fungal species, analysing the virulence of Heterobasidion annosum s.s., a necrotrophic pathogen, on its hosts Picea abies and Pinus sylvestris. From a set of 33,018 single nucleotide polymorphisms (SNP) in 23 haploid isolates, twelve SNP markers distributed on seven contigs were associated with virulence (P<0.0001). Four of the contigs harbour known virulence genes from other fungal pathogens and the remaining three harbour novel candidate genes. Two contigs link closely to virulence regions recognized previously by QTL mapping in the congeneric hybrid H. irregulare × H. occidentale. Our study demonstrates the efficiency of GWA studies for dissecting important complex traits of small populations of non-model haploid organisms with small genomes.
Collapse
Affiliation(s)
- Kerstin Dalman
- Uppsala BioCenter, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | | | | | | | | | | |
Collapse
|
27
|
Manning VA, Pandelova I, Dhillon B, Wilhelm LJ, Goodwin SB, Berlin AM, Figueroa M, Freitag M, Hane JK, Henrissat B, Holman WH, Kodira CD, Martin J, Oliver RP, Robbertse B, Schackwitz W, Schwartz DC, Spatafora JW, Turgeon BG, Yandava C, Young S, Zhou S, Zeng Q, Grigoriev IV, Ma LJ, Ciuffetti LM. Comparative genomics of a plant-pathogenic fungus, Pyrenophora tritici-repentis, reveals transduplication and the impact of repeat elements on pathogenicity and population divergence. G3 (BETHESDA, MD.) 2013; 3:41-63. [PMID: 23316438 PMCID: PMC3538342 DOI: 10.1534/g3.112.004044] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 11/02/2012] [Indexed: 12/31/2022]
Abstract
Pyrenophora tritici-repentis is a necrotrophic fungus causal to the disease tan spot of wheat, whose contribution to crop loss has increased significantly during the last few decades. Pathogenicity by this fungus is attributed to the production of host-selective toxins (HST), which are recognized by their host in a genotype-specific manner. To better understand the mechanisms that have led to the increase in disease incidence related to this pathogen, we sequenced the genomes of three P. tritici-repentis isolates. A pathogenic isolate that produces two known HSTs was used to assemble a reference nuclear genome of approximately 40 Mb composed of 11 chromosomes that encode 12,141 predicted genes. Comparison of the reference genome with those of a pathogenic isolate that produces a third HST, and a nonpathogenic isolate, showed the nonpathogen genome to be more diverged than those of the two pathogens. Examination of gene-coding regions has provided candidate pathogen-specific proteins and revealed gene families that may play a role in a necrotrophic lifestyle. Analysis of transposable elements suggests that their presence in the genome of pathogenic isolates contributes to the creation of novel genes, effector diversification, possible horizontal gene transfer events, identified copy number variation, and the first example of transduplication by DNA transposable elements in fungi. Overall, comparative analysis of these genomes provides evidence that pathogenicity in this species arose through an influx of transposable elements, which created a genetically flexible landscape that can easily respond to environmental changes.
Collapse
Affiliation(s)
- Viola A. Manning
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331
| | - Iovanna Pandelova
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331
| | - Braham Dhillon
- Department of Forest Sciences, University of British Columbia, Vancouver, British Columbia, Canada, V6T 1Z4
| | - Larry J. Wilhelm
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331
- Carbone/Ferguson Laboratories, Division of Neuroscience, Oregon National Primate Research Center (ONPRC), Beaverton, Oregon 97006
| | - Stephen B. Goodwin
- USDA–Agricultural Research Service, Purdue University, West Lafayette, Indiana 47907
| | | | - Melania Figueroa
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331
- USDA-Agricultural Research Service, Forage Seed and Cereal Research Unit, Oregon State University, Corvallis, Oregon 97331
| | - Michael Freitag
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331
- Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon 97331
| | - James K. Hane
- Commonwealth Scientific and Industrial Research Organization−Plant Industry, Centre for Environment and Life Sciences, Floreat, Western Australia 6014, Australia
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, Centre National de la Recherche Scientifique, 13288 Marseille cedex 9, France
| | - Wade H. Holman
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331
| | - Chinnappa D. Kodira
- The Broad Institute, Cambridge, Massachusetts 02142
- Roche 454, Branford, Connecticut 06405
| | - Joel Martin
- US DOE Joint Genome Institute, Walnut Creek, California 94598
| | - Richard P. Oliver
- Australian Centre for Necrotrophic Fungal Pathogens, Department of Environment and Agriculture, Curtin University, Bentley, Western Australia 6845, Australia
| | - Barbara Robbertse
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, Centre National de la Recherche Scientifique, 13288 Marseille cedex 9, France
| | | | - David C. Schwartz
- Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics, UW Biotechnology Center, University of Wisconsin–Madison, Madison, Wisconsin 53706
| | - Joseph W. Spatafora
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331
| | - B. Gillian Turgeon
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14850
| | | | - Sarah Young
- The Broad Institute, Cambridge, Massachusetts 02142
| | - Shiguo Zhou
- Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics, UW Biotechnology Center, University of Wisconsin–Madison, Madison, Wisconsin 53706
| | | | | | - Li-Jun Ma
- The Broad Institute, Cambridge, Massachusetts 02142
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003
| | - Lynda M. Ciuffetti
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331
- Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon 97331
| |
Collapse
|
28
|
Pandelova I, Figueroa M, Wilhelm LJ, Manning VA, Mankaney AN, Mockler TC, Ciuffetti LM. Host-selective toxins of Pyrenophora tritici-repentis induce common responses associated with host susceptibility. PLoS One 2012; 7:e40240. [PMID: 22792250 PMCID: PMC3391247 DOI: 10.1371/journal.pone.0040240] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 06/03/2012] [Indexed: 12/16/2022] Open
Abstract
Pyrenophora tritici-repentis (Ptr), a necrotrophic fungus and the causal agent of tan spot of wheat, produces one or a combination of host-selective toxins (HSTs) necessary for disease development. The two most studied toxins produced by Ptr, Ptr ToxA (ToxA) and Ptr ToxB (ToxB), are proteins that cause necrotic or chlorotic symptoms respectively. Investigation of host responses induced by HSTs provides better insight into the nature of the host susceptibility. Microarray analysis of ToxA has provided evidence that it can elicit responses similar to those associated with defense. In order to evaluate whether there are consistent host responses associated with susceptibility, a similar analysis of ToxB-induced changes in the same sensitive cultivar was conducted. Comparative analysis of ToxA- and ToxB-induced transcriptional changes showed that similar groups of genes encoding WRKY transcription factors, RLKs, PRs, components of the phenylpropanoid and jasmonic acid pathways are activated. ROS accumulation and photosystem dysfunction proved to be common mechanism-of-action for these toxins. Despite similarities in defense responses, transcriptional and biochemical responses as well as symptom development occur more rapidly for ToxA compared to ToxB, which could be explained by differences in perception as well as by differences in activation of a specific process, for example, ethylene biosynthesis in ToxA treatment. Results of this study suggest that perception of HSTs will result in activation of defense responses as part of a susceptible interaction and further supports the hypothesis that necrotrophic fungi exploit defense responses in order to induce cell death.
Collapse
Affiliation(s)
- Iovanna Pandelova
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
| | - Melania Figueroa
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
- United States Department of Agriculture, Agricultural Research Service, Forage Seed and Cereal Research Unit, Oregon State University, Corvallis, Oregon, United States of America
| | - Larry J. Wilhelm
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
| | - Viola A. Manning
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
| | - Aakash N. Mankaney
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
| | - Todd C. Mockler
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
- The Donald Danforth Plant Science Center, St. Louis, Missouri, United States of America
| | - Lynda M. Ciuffetti
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
- * E-mail:
| |
Collapse
|
29
|
Déon M, Bourré Y, Gimenez S, Berger A, Bieysse D, de Lamotte F, Poncet J, Roussel V, Bonnot F, Oliver G, Franchel J, Seguin M, Leroy T, Roeckel-Drevet P, Pujade-Renaud V. Characterization of a cassiicolin-encoding gene from Corynespora cassiicola, pathogen of rubber tree (Hevea brasiliensis). PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 185-186:227-237. [PMID: 22325885 DOI: 10.1016/j.plantsci.2011.10.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 10/17/2011] [Accepted: 10/21/2011] [Indexed: 05/26/2023]
Abstract
Corynespora Leaf Fall (CLF) is a major disease of rubber tree (Hevea brasiliensis) caused by the Ascomycota Corynespora cassiicola. Here we describe the cloning and characterization of a gene encoding cassiicolin (Cas), a glycosylated cystein-rich small secreted protein (SSP) identified as a potential CLF disease effector in rubber tree. Three isolates with contrasted levels of aggressiveness were analyzed comparatively. The cassiicolin gene was detected - and the toxin successfully purified - from the isolates with high and medium aggressiveness (CCP and CCAM3 respectively) but not from the isolate with the lowest aggressiveness (CCAM1), suggesting the existence of a different disease effector in the later. CCP and CCAM3 carried strictly identical cassiicolin genes and produced toxins of identical mass, as evidence by mass spectrometry analysis, thus suggesting conserved post-translational modifications in addition to sequence identity. The differences in aggressiveness between CCP and CCAM3 may be attributed to differences in cassiicolin transcript levels rather than qualitative variations in cassiicolin structure. Cassiicolin may play an important role in the early phase of infection since a peak of cassiicolin transcripts occurred in 1 or 2 days after inoculation (before the occurrence of the first symptoms), in both the tolerant and the susceptible cultivars.
Collapse
Affiliation(s)
- Marine Déon
- CIRAD, UMR AGAP, F-63000 Clermont-Ferrand, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Andrie RM, Ciuffetti LM. Pyrenophora bromi, causal agent of brownspot of bromegrass, expresses a gene encoding a protein with homology and similar activity to Ptr ToxB, a host-selective toxin of wheat. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2011; 24:359-67. [PMID: 21091157 DOI: 10.1094/mpmi-06-10-0142] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Ptr ToxB, encoded by ToxB, is one of multiple host-selective toxins (HST) produced by the wheat pathogen Pyrenophora tritici-repentis. Homologs of ToxB are found in several ascomycetes, including sister species Pyrenophora bromi, causal agent of brownspot of bromegrass. Due to the close evolutionary relatedness of P. tritici-repentis and P. bromi and that of their grass hosts, we hypothesized that homologs of ToxB in P. bromi may act as HST in the disease interaction between P. bromi and bromegrass. A representative set of transcriptionally active P. bromi ToxB genes were heterologously expressed in Pichia pastoris and the resultant proteins tested for their ability to act as HST on bromegrass. The tested Pyrenophora bromi ToxB (Pb ToxB) proteins were not toxic to bromegrass; thus, Pb ToxB does not appear to function as an HST in the P. bromi-bromegrass interaction. Instead, we revealed that the Pb ToxB proteins can be toxic to Ptr ToxB-sensitive wheat, at levels similar to Ptr ToxB, and the corresponding P. bromi ToxB genes are expressed in P. bromi-inoculated wheat. Our data suggest that P. bromi possesses the potential to become a wheat pathogen and highlights the importance of investigating the interaction between P. bromi and wheat.
Collapse
Affiliation(s)
- Rachael M Andrie
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, USA
| | | |
Collapse
|
31
|
Sun XC, Bockus W, Bai G. Quantitative trait loci for resistance to Pyrenophora tritici-repentis race 1 in a Chinese wheat. PHYTOPATHOLOGY 2010; 100:468-73. [PMID: 20373968 DOI: 10.1094/phyto-100-5-0468] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Tan spot, caused by Pyrenophora tritici-repentis, is an economically important foliar disease of wheat worldwide. Eight races of the pathogen have been characterized on the basis of their ability to cause necrosis or chlorosis in a set of differential wheat lines. Race 1 produces two host-selective toxins, Ptr ToxA and Ptr ToxC, that induce necrosis and chlorosis, respectively, on leaves of sensitive wheat genotypes. A population of recombinant inbred lines was developed from a cross between Chinese landrace Wangshuibai (resistant) and Chinese breeding line Ning7840 (highly susceptible) to identify chromosome regions harboring quantitative trait loci (QTL) or genes for tan spot resistance. Plants were inoculated at the four-leaf stage in a greenhouse and percent leaf area diseased was scored 7 days after inoculation. Two QTL for resistance to race 1 were mapped to the short arms of chromosomes 1A and 2B in the population. The QTL on 1AS, designated as QTs.ksu-1AS, showed a major effect and accounted for 39% of the phenotypic variation; the QTL on 2BS, designated as QTs.ksu-2BS, explained 4% of the phenotypic variation for resistance. A toxin infiltration experiment demonstrated that both parents were insensitive to Ptr ToxA, suggesting that the population was most likely segregating for reaction to chlorosis, not necrosis. The markers closely linked to the QTL should be useful for marker-assisted selection in wheat-breeding programs.
Collapse
Affiliation(s)
- Xiao-Chun Sun
- Department of Anatomy, Kansas State University, Manhattan, KS 66506, USA
| | | | | |
Collapse
|
32
|
Lepoint P, Renard ME, Legrève A, Duveiller E, Maraite H. Genetic diversity of the mating type and toxin production genes in Pyrenophora tritici-repentis. PHYTOPATHOLOGY 2010; 100:474-83. [PMID: 20373969 DOI: 10.1094/phyto-100-5-0474] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Pyrenophora tritici-repentis, the causal agent of tan spot on wheat, is a homothallic loculoascomycete with a complex race structure. The objectives of this study were to confirm the homothallic nature of the pathogen, characterize mating type diversity and toxin production genes in a global collection of strains, and analyze how these traits are associated between each other and with existing races. The pseudothecia production capacity, race identification, mating type locus (MAT), internal transcribed spacer, and glyceraldehyde-3-phosphate dehydrogenase regions were analyzed in a selection of 88 strains originating from Europe, North and South America, North Africa, and Central and South Asia. Some (60%) strains produced pseudothecia containing ascospores, independent of their origin. Race identification obtained using the multiplex polymerase chain reaction targeting host-selective toxin (HST) genes was consistent, overall, with the results based on the inoculation of a set of differential wheat cultivars and confirmed the predominance of race 1/2 strains ( approximately 83%). However, discrepancies in race identification, differences from the reference tester strains, and atypical ToxA profiles suggest the presence of new races and HSTs. The MAT1-1 and MAT1-2 coding regions are consecutively arranged in a single individual, suggesting putative heterothallic origin of P. tritici-repentis. Upstream from the MAT is an open reading frame of unknown function (ORF1) containing a MAT-specific degenerate carboxy-terminus. The phylogenetic analysis of the MAT locus reveals two distinct groups, unlinked to geographical origin or ToxA profile. Group I, the best-represented group, is associated with typical tan spot lesions caused by races 1, 2, 3, and 5 on wheat. It is more homogenous than group II encompassing race 4 strains, as well as isolates associated primarily with small spot lesions on wheat leaves or other hosts. Group II could contain several distinct taxa.
Collapse
Affiliation(s)
- P Lepoint
- Unité de Phytopathologie, Université Catolholique de Louvain, Louvain-la-Neuve, Belgium
| | | | | | | | | |
Collapse
|
33
|
Ali S, Gurung S, Adhikari TB. Identification and Characterization of Novel Isolates of Pyrenophora tritici-repentis from Arkansas. PLANT DISEASE 2010; 94:229-235. [PMID: 30754257 DOI: 10.1094/pdis-94-2-0229] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Tan spot, caused by Pyrenophora tritici-repentis, is an important foliar disease of wheat (Triticum aestivum) worldwide. In a preliminary study, P. tritici-repentis isolates from Arkansas were shown to vary in virulence relative to isolates from other regions of the United States. Therefore, the aim of the current study was to characterize both pathogenic and molecular variations in P. tritici-repentis isolates from Arkansas. The virulence of 93 isolates of P. tritici-repentis was evaluated by inoculating five differential wheat cultivars/lines. Based on virulence phenotypes, 63 isolates were classified as race 1, and 30 isolates were assigned to race 3. A subset of 42 isolates was selected for molecular characterization with the presence or absence of the ToxA and ToxB genes. The results showed that 36 isolates out of 42 tested by polymerase chain reaction (PCR) and Southern analysis lacked the ToxA and ToxB genes. Six isolates harboring the ToxA and ToxB genes induced necrosis and chlorosis on Glenlea and 6B365, respectively. Thirteen ToxA gene-deficient isolates also caused necrosis and chlorosis on Glenlea and 6B365, respectively; however, they did not fit current race classification. In contrast, the remaining 23 ToxA gene-deficient isolates did not cause necrosis, but induced chlorosis on 6B365, showing a disease profile for race 3. When the virulence of AR LonB2 (an isolate with unclassified race) was compared with known races 1, 3, and 5 of P. tritici-repentis on 20 winter wheat cultivars from Arkansas, the virulence phenotypes differed substantially. Taken together, the ToxA and ToxB gene-deficient isolates of P. tritici-repentis that induce necrosis and/or chlorosis may produce a novel toxin(s) on wheat.
Collapse
Affiliation(s)
- Shaukat Ali
- Department of Plant Pathology, North Dakota State University, NDSU Dept. 7660, P.O. Box 6050, Fargo, ND 58108
| | - Suraj Gurung
- Department of Plant Pathology, North Dakota State University, NDSU Dept. 7660, P.O. Box 6050, Fargo, ND 58108
| | - Tika B Adhikari
- Department of Plant Pathology, North Dakota State University, NDSU Dept. 7660, P.O. Box 6050, Fargo, ND 58108
| |
Collapse
|
34
|
Chu CG, Friesen TL, Xu SS, Faris JD. Identification of novel tan spot resistance loci beyond the known host-selective toxin insensitivity genes in wheat. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2008; 117:873-81. [PMID: 18575834 DOI: 10.1007/s00122-008-0826-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Accepted: 06/09/2008] [Indexed: 05/07/2023]
Abstract
Tan spot, caused by Pyrenophora tritici-repentis, is a destructive foliar disease of wheat causing significant yield reduction in major wheat growing areas throughout the world. The objective of this study was to identify quantitative trait loci (QTL) conferring resistance to tan spot in the synthetic hexaploid wheat (SHW) line TA4152-60. A doubled haploid (DH) mapping population derived from TA4152-60 x ND495 was inoculated with conidia produced by isolates of each of four virulent races of P. tritici-repentis found in North America. QTL analysis revealed a total of five genomic regions significantly associated with tan spot resistance, all of which were contributed by the SHW line. Among them, two novel QTLs located on chromosome arms 2AS and 5BL conferred resistance to all isolates tested. Another novel QTL on chromosome arm 5AL conferred resistance to isolates of races 1, 2 and 5, and a QTL specific to a race 3 isolate was detected on chromosome arm 4AL. None of these QTLs corresponded to known host selective toxin (HST) insensitivity loci, but a second QTL on chromosome arm 5BL conferred resistance to the Ptr ToxA producing isolates of races 1 and 2 and corresponded to the Tsn1 (Ptr ToxA sensitivity) locus. This indicates that the wheat-P. tritici-repentis pathosystem is much more complex than previously thought and that selecting for toxin insensitivity alone will not necessarily lead to tan spot resistance. The markers associated with the QTLs identified in this work will be useful for deploying the SHW line as a tan spot resistance source in wheat breeding.
Collapse
Affiliation(s)
- C-G Chu
- Department of Plant Sciences, North Dakota State University, Fargo, ND 58105, USA
| | | | | | | |
Collapse
|
35
|
Singh S, Bockus WW, Sharma I, Bowden RL. A Novel Source of Resistance in Wheat to Pyrenophora tritici-repentis Race 1. PLANT DISEASE 2008; 92:91-95. [PMID: 30786378 DOI: 10.1094/pdis-92-1-0091] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Tan spot, caused by the fungus Pyrenophora tritici-repentis, causes serious yield losses in wheat (Triticum aestivum) and many other grasses. Race 1 of the fungus, which produces the necrosis toxin Ptr ToxA and the chlorosis toxin Ptr ToxC, is the most prevalent race in the Great Plains of the United States. Wheat genotypes with useful levels of resistance to race 1 have been deployed, but this resistance reduces damage by only 50 to 75%. Therefore, new sources of resistance to P. tritici-repentis are needed. Recombinant inbred lines developed from a cross between the Indian spring wheat cvs. WH542 (resistant) and HD29 (moderately susceptible) were evaluated for reaction to race 1 of the fungus. Composite interval mapping revealed quantitative trait loci (QTL) on the short arm of chromosome 3A explaining 23% of the phenotypic variation, and the long arm of chromosome 5B explaining 27% of the variation. Both resistance alleles were contributed by the WH542 parent. The QTL on 5BL is probably tsn1, which was described previously. The 3AS QTL (QTs.ksu-3AS) on 3AS is a novel QTL for resistance to P. tritici-repentis race 1. The QTL region is located in the most distal bin of chromosome 3AS in a 2.2-centimorgan marker interval. Flanking markers Xbarc45 and Xbarc86 are suitable for marker-assisted selection for tan spot resistance.
Collapse
Affiliation(s)
- Sukhwinder Singh
- Department of Plant Pathology, Kansas State University, Manhattan 66506
| | - William W Bockus
- Department of Plant Pathology, Kansas State University, Manhattan 66506
| | - Indu Sharma
- Department of Plant Breeding, Genetics and Biotechnology, Punjab Agricultural University, Ludhiana, India
| | - Robert L Bowden
- United States Department of Agriculture-Agricultural Research Service, Manhattan, KS 66506
| |
Collapse
|
36
|
Andrie RM, Schoch CL, Hedges R, Spatafora JW, Ciuffetti LM. Homologs of ToxB, a host-selective toxin gene from Pyrenophora tritici-repentis, are present in the genome of sister-species Pyrenophora bromi and other members of the Ascomycota. Fungal Genet Biol 2007; 45:363-77. [PMID: 18226934 DOI: 10.1016/j.fgb.2007.10.014] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Revised: 10/20/2007] [Accepted: 10/23/2007] [Indexed: 11/29/2022]
Abstract
Pyrenophora tritici-repentis requires the production of host-selective toxins (HSTs) to cause the disease tan spot of wheat, including Ptr ToxA, Ptr ToxB, and Ptr ToxC. Pyrenophora bromi, the species most closely related to P. tritici-repentis, is the causal agent of brown leaf spot of bromegrass. Because of the relatedness of P. bromi and P. tritici-repentis, we investigated the possibility that P. bromi contains sequences homologous to ToxA and/or ToxB, the products of which may be involved in its interaction with bromegrass. Multiplex polymerase chain reaction (PCR) revealed the presence of ToxB-like sequences in P. bromi and high-fidelity PCR was used to clone several of these loci, which were subsequently confirmed to be homologous to ToxB. Additionally, Southern analysis revealed ToxB from P. bromi to have a multicopy nature similar to ToxB from P. tritici-repentis. A combination of phylogenetic and Southern analyses revealed that the distribution of ToxB extends further into the Pleosporaceae, and a search of available fungal genomes identified a distant putative homolog in Magnaporthe grisea, causal agent of rice blast. Thus, unlike most described HSTs, ToxB homologs are present across a broad range of plant pathogenic ascomycetes, suggesting that it may have arose in an early ancestor of the Ascomycota.
Collapse
Affiliation(s)
- Rachael M Andrie
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
| | | | | | | | | |
Collapse
|